In many medical or clinical settings the delivery of intravenous solutions necessitates isolation of component solutions until immediately prior to patient injection. A common, widely-used component solution pair is aminosyn II/dextrose. This solution pair discolors if mixed prior to sterilization, making it unmarketable and unusable. Other component solution pairs include potassium phosphate/calcium gluconate, potassium phosphate/TPN electrolytes, and sodium phosphate/calcium gluconate. Upon standing over time each of the above solution pairs, once mixed, tend to form insoluble precipitates which render them useless for intravenous injection. Solution stability and effectiveness are insured by separation until just prior to use, followed by adequate mixing.
Early concern over such precipitation and discoloration fostered the use of multiple intravenous bags, each with its own delivery stream. Mixing component solutions in this manner solved these problems, but created others. Multiple intravenous bags necessitate extra accessory injection equipment and require that each be sterilized. The increased potential for mechanical failure and introduction of aseptic conditions, as well as difficult and time-consuming set-up procedures are the primary problems associated with this means of intravenous injection.
The search for an efficient, effective intravenous injection system meeting the requirements stated above has been an ongoing concern in the art. One approach, which has been used with certain success, involves the use of a multi-chamber bag system utilizing upper and lower chambers (chambers A and B, respectively) separated by a clamped, narrow constricture. Such multi-chamber bags of the prior art typically include a clothes-pin type clamp which is opened just prior to use, enabling the contents from chamber A to flow slowly and mix with that in chamber B. Once completed, the clamp closes off chamber A. The combined component solutions are then injected intravenously from chamber B. Such multi-chamber intravenous bag systems have eliminated the need for pre-measuring component solutions and have overcome the aforementioned precipitation and discoloration concerns.
However, the prior art has associated with it a number of significant problems and deficiencies. Most are related to constricted flow from an upper chamber into the lower, and result from the type of multi-chamber bag apparatus currently used.
One major problem is that component mixing is slow and inefficient. Typically, the component in chamber A must be, in large part, squeezed into chamber B. At the same time all air must be removed from chamber A. The result is an unnecessary expenditure of time and, almost without exception, wasted component through adherence to chamber walls. Precision mixing is difficult. Devices of the prior art which include the aforementioned clothes-pin type clamp also permit escape of air into the unused upper chamber. Such loss of air from the lower chamber tends to distort volumetric graduation of the lower chamber. As such, graduated delivery from chamber B is difficult.
Another significant concern with certain multi-chamber bag systems of the prior art is that, given the self-contained nature of chamber B, introduction of additional components into the multi-chamber system, as is often desirable, is difficult at best. Because of this, the prior art resorts to the use of one or more additional bags, hung beside the multi-chamber bag, each with its own delivery stream which must then be combined with other streams before patient injection. However, the mechanical and sterilization problems mentioned above remain. In some instances, addition of a third component to chamber B is possible, but with certain widely-used multi-chamber bags the amount which can be added is limited to about 10-20 milliliters because of the limited excess capacity in chamber B once the component from chamber A has been added.
Another significant problem is that once chamber A is emptied that portion of the bag is sealed off and no longer useful, resulting in an inefficient and costly use of materials.
Another significant problem is that assembly of multi-chamber bag systems of the prior art is very labor intensive necessitating the use and time of several individuals.
In summary, a considerable number of drawbacks and problems exist in the art relating to multi-chamber intravenous bag systems. There is a need for an improved multi-chamber intravenous bag apparatus to fully utilize the advantages of a multi-chamber intravenous bag system.